Name: designed for molecular recycling: a lignin-derived semi-aromatic biobased polymer
Uploaded: 2020-11-30T14:00:00
Description: Watch this Scientific Journal Video about Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer at JoVE.com

作者感谢荷兰科学研究组织（NWO）的财政支持（授予杰克·范·希恩德尔023.007.020）。

1. 绿色克诺维纳格尔凝结注射器醛对西纳皮尼奇酸与 5 摩尔% 碳酸氢铵
<ol><li>将马洛尼克酸（20.81 克，200.0 mmol）与注射器醛 （36.4 克， 200.0 mmol） 一起加入 250 mL 圆底烧瓶中。溶解两个成分在20.0 mL乙酸乙酸乙酸酯，并添加碳酸氢铵（790毫克，10.0毫米醇）到烧瓶。 注：为确保完全完成凝结反应，旋转蒸发器可用于蒸馏乙酸乙酸乙酯并浓缩反应混合物，从而产生无溶剂反应。</li>
	<li>将反应混合?...

<ol>
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当二氢酸在反应容器中加热时，启动材料的升华发生，当应用真空时，这种效果得到增强。乙酰化已对二氢酸进行，以避免升华。克里切多夫等人12日、27日承认，不仅乙酰化，而且类似的二寡聚化也发生了。然而，这些酯化单体和寡聚物不再升华，适合作为单体熔化聚合物28。此外，从4-乙氧二氢酸的预聚合物的形成证实了假设反应机...

与聚合物废物的焚烧相比，化学回收提供了回收单体的可能性。化学回收是聚合物材料技术寿命结束时的一个合乎逻辑的选择，因为这些聚合物材料是化学1生产的。有两种方法可以化学地回收聚合物材料，热解和分子回收2。通过热解，聚合物材料通过极端条件3、4转化为高价值产品。分子回收是利用去聚合回收起始材料的有效方法。去聚合后，单体单元可再聚合成处女聚合材料5。需要有合适的单体来大规模地应用分子回收。目前的塑料问题决定了社会需要坚固耐用的聚合物材料。同时，也更希望同样的聚合物材料易于回收利用，在环境中不耐用。电流聚合物材料具有良好的热和机械性能，不容易去聚合。
利格宁，常见于血管植物，占世界天然碳含量的30%，是仅次于纤维素的第二大生物聚合物。褐金具有复杂的无定形结构，似乎是替代从化石材料中提取的芳香剂的合适替代品。木质素的三维结构为木材提供强度和刚度，以及抗降解。从化学上讲，木质素是一种非常复杂的多酚热集。它由三种不同的甲氧化苯丙烷结构的不同组成组成。西林吉尔、瓜亚基和p-羟基苯基（通常分别缩写为S、G和H）来自单利尼诺西纳皮尔醇、针叶醇和p-库马里尔酒精7。这些单位的分布不同，每个生物质类型，软木，例如，主要包括瓜亚基单位和硬木的瓜亚基和注射器单位8，9。可再生的天然资源，如树木和植物，是生产重新设计的单体创新聚合物材料10的理想。这些单体，从天然来源分离和合成，聚合到所谓的生物基聚合物11。
芳香性碳酸是几个数量级比同等的药化碳酸少12。各种商业聚酯使用芳香的碳酸，而不是药酸。因此，聚酯纺织品中由聚（乙烯四甲酸酯）纤维制成的纤维在洗涤过程中几乎对水解麻木不仁，例如，雨13。当需要聚酯分子回收时，建议在聚合物的积累中使用脂肪酯。
对于上述原因，我们已研究了用4-羟基-3，5-二氧二氢辛酸制造聚酯的可能性。克里切尔多夫15号、迈尔16号和米勒17号、18号先前的研究表明，使用4-羟基-3，5-二氧-二氢辛酸制造聚合物是具有挑战性的。脱卡和交联阻碍了聚合，因此限制了这些合成器的成功。此外，多聚变的机制仍然不清楚。论文描述了聚酯聚（二氢酸）可以定期合成和高产的条件，从而为使用分子可回收的半芳香聚酯铺平了道路。
我们开发了一种绿色和高效的方法，利用注射器醛和恶性酸19，20之间的凝结反应合成西纳皮尼酸。在此绿色克诺维纳格尔之后，氢化产生二氢酸，适用于可逆多聚化。本出版物可视化分子可回收聚合物聚（二氢酸）的合成步骤，指木质素的基础单位，称为聚S。在分析聚合物材料后，聚氨酯在相对有利的条件下去聚聚到单体二氢酸中，并反复再聚。

<table>
	<tbody>
		<tr>
			<td>Reaction 1: Green Knoevenagel condensation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium bicarbonate</td>
			<td>Sigma Aldrich</td>
			<td>&#62;99%</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Boom</td>
			<td>Technical grade</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethyl acetate</td>
			<td>Macron</td>
			<td>99.8%</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid</td>
			<td>Boom</td>
			<td>37%</td>
			<td></td>
		</tr>
		<tr>
			<td>Malonic acid</td>
			<td>Sigma Aldrich</td>
			<td>99%</td>
			<td>used as received</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sigma Aldrich</td>
			<td>&#62;99.7%</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringaldehyde</td>
			<td>Sigma Aldrich</td>
			<td>98%</td>
			<td>used as received</td>
		</tr>
		<tr>
			<td>Reaction 2: Hydrogenation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium sulfate</td>
			<td>Macron</td>
			<td>99%</td>
			<td>dried</td>
		</tr>
		<tr>
			<td>Raney&#8482; nickel</td>
			<td>Sigma Aldrich</td>
			<td>&#62;89%</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>Boom</td>
			<td>Technical grade</td>
			<td>dissolved</td>
		</tr>
		<tr>
			<td>Reaction 3: Acetylation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic anhydride</td>
			<td>Macron</td>
			<td>&#62;98%</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Macron</td>
			<td>&#62;99.5%</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium acetate</td>
			<td>Sigma Aldrich</td>
			<td>&#62;99%</td>
			<td></td>
		</tr>
		<tr>
			<td>Reaction 4A: Polymerisation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1,2-xylene</td>
			<td>Macron</td>
			<td>&#62;98%</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>Boom</td>
			<td>Technical grade</td>
			<td>finely powdered</td>
		</tr>
		<tr>
			<td>Zinc(II)acetate</td>
			<td>Sigma Aldrich</td>
			<td>99.99%</td>
			<td></td>
		</tr>
		<tr>
			<td>Reaction 4B: Depolymerisation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>Boom</td>
			<td>Technical grade</td>
			<td>dissolved</td>
		</tr>
		<tr>
			<td>Sulfuric acid</td>
			<td>Macron</td>
			<td>100%</td>
			<td></td>
		</tr>
		<tr>
			<td>Analysis</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>CDCl3</td>
			<td>Cambride Isotope Laboratories, Inc.</td>
			<td>99.5%</td>
			<td></td>
		</tr>
		<tr>
			<td>CF3COOD</td>
			<td>Cambride Isotope Laboratories, Inc.</td>
			<td>98%</td>
			<td></td>
		</tr>
		<tr>
			<td>Dimethylformamide</td>
			<td>Macron</td>
			<td>&#62;99.9%</td>
			<td></td>
		</tr>
		<tr>
			<td>Hexafluoro-2-propanol</td>
			<td>TCI Chemicals</td>
			<td>&#62;99%</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Macron</td>
			<td>&#62;99.8%</td>
			<td></td>
		</tr>
		<tr>
			<td>Tetrahydrofuran</td>
			<td>Macron</td>
			<td>&#62;99.9%</td>
			<td></td>
		</tr>
	</tbody>
</table>

designed for molecular recycling: a lignin-derived semi-aromatic biobased polymer

化学可回收生物聚合物的发展为追求循环经济提供了机遇。化学可回收生物聚合物在使用阶段后的处置阶段积极努力解决聚合物材料问题。本文对生物基半芳烃聚酯的生产进行了描述和可视化，这种聚酯完全可以从木质素等生物量中提取。本文中描述的聚合物聚氨酯具有与某些常用塑料（如 PET）相似的热性能。我们开发了一种绿色克诺维纳格尔反应，它可以有效地产生芳香醛和马洛尼克酸的单体。这种反应已被证明是可扩展的，并且具有非常低的计算电子因子。这些以利格诺植物化学物质为起点的聚酯显示出高效的分子回收利用，损失最小。聚酯聚（二氢酸）（聚S）是这些半芳香聚酯的示例，并描述了聚合、去聚合和再聚合。

西纳皮尼酸是使用绿色克诺维纳凝结剂从注射器醛中高纯度和高产量（>95%）合成的。（支持信息：图S1）电子因子表示废物产生，其中较高的数字表示更多的废物。电子因子的计算方法是获取总材料投入，减去所需最终产品的量，并将整个产品除以最终产品的量。这种绿色克诺维纳格尔凝结物的电子因子为1.0， 可以计算： [（29.81 克马洛尼克酸 = 36.4 克注射器醛 = 0.790 克碳酸氢铵 = 18....

Watch this Scientific Journal Video about Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer at JoVE.com

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer

这里介绍了对循环材料经济采取闭环方法的一个例子。整个可持续循环由生物基半芳烃聚酯设计，通过聚合、去聚合，然后重新聚合，其产量或最终特性仅略有变化。

专为分子回收而设计：一种褐宁衍生的半芳烃生物基聚合物

The development of chemically recyclable biopolymers offers opportunities within the pursuit of a circular economy. Chemically recyclable biopolymers make ...

Throughout the synthesis described in this paper provides a way to produce a new polymeric material specifically designed for molecular recycling, which is a way of chemical recycling. The depolarization and repolarization of the foreign material poly-S creates a fully sustainable cycle, which is a proof of concept for the future of polymers. The polymer waste of the world accumulates.For instance in the ocean, as the plastic soup, which could be prevented by introducing molecularly recyclable polymers. The polymer presented is an example of a polymeric material designed for molecular recycling. This in our opinion, should be implemented in other materials to prevent accumulation in nature.Green Knoevenagel reaction and subsequent steps have been designed for and by our undergraduated students. So certain robustness is already implemented in these reaction steps. The COVID-19 pandemic creates a situation where online learning becomes more important than ever.Visualization of these experiments helps us and others to deepen practical chemical education. Begin by adding 20.81 grams of malonic acid and 36.4 grams of syringaldehyde to a 215 milliliter round bottom flask. Dissolve both constituents in 20 milliliters of ethyl acetate and add 719 milligrams of ammonia bicarbonate to the flask.Mix and distill the solvent with a water bath. Keep the reaction mixture at 90 degrees Celsius for two hours in the open flask without stirring for complete conversion to sinapinic acid. In the work-up of the sinapinic acid product, dissolve the residue in 100 milliliters of a saturated aqueous sodium bicarbonate solution, then transfer the solution to a beaker, and acidify it to a pH two.Using six molar hydrogen chloride, separate the resulting residue by vacuum filtration and wash it with demineralized water. Charge a 450 milliliters flask with 33.6 grams sinapinic acid. Dissolve the sinapinic acid in 300 milliliters of two molar sodium hydroxide solution, and add 1.5 grams of nickel slurry before fitting the flask to the operators.Pressurize the reactor with three bar of hydrogen gas and mechanically shake the reaction at 80 degrees Celsius for three hours. Cool the reactor to room temperature and depressurize slowly. Recover most of the nickel catalyst with a magnet, then filter the solution.Acidify the solution with four molar hydrogen chloride solution to a pH of two, then perform an extraction with ethyl acetate. Remove the solvent under reduced pressure after drying over magnesium sulfate and dry the dihydrosinapinic acid at 60 degrees Celsius in a vacuum oven. Add 22.6 grams dihydrosinapinic acid to a 250 milliliter round bottom flask.Followed by 14.2 milliliters of acetic anhydride and 0.82 grams of sodium acetate. Heat the solution to 90 degrees Celsius while stirring for one hour for complete conversion of dihydrosinapinic acid to 4-Acetoxy-dihydrosinapinic acid, and it's acetylated oligomers. Dissolve the solid in 25 milliliters of acetone precipitated into 250 milliliters of 0.1 molar hydrogen chloride, then filtered on the vacuum.Add the monomers 20.8 grams of 4-Acetoxy-dihydrosinapinic acid and prepolymer to a 100 milliliter round bottom flask. Then add 400 milligrams of finely powdered sodium hydroxide, heat the reaction mixture for three hours at a set temperature of 140 degrees Celsius in the open flask while staring at 100 RPM. Set up a solvent assisted polymerization by adding 180 milligrams of zinc two acetate and 25.0 milliliters of 1, 2-xylene to the flask, then raise the set temperature to 160 degrees Celsius.Reflux the mixture at 144 degrees Celsius for three hours with constant water and acetic acid removal using Dean-Stark head. Cool the reaction mixture down and remove the 1, 2-xylene by applying a vacuum. Raise the temperature to 240 degrees Celsius during the final stage of the polymerization and apply a high vacuum for 30 minutes.Cool the polymer poly-S to room temperature and wash it with methanol to eliminate dihydrogen sinapinic acid and prepolymers. The obtained product should be a light brown solid. Finally grind and serve the poly-S into particles smaller than 180 micrometres to measure hydrolytic degradation.Load several test tubes with 20 milligrams of poly-S and add one milliliter of one molar sodium hydroxide solution. Incubate the tubes at three different temperatures with an agitation of 500 RPM. Neutralize the test tubes at regular time intervals with one milliliter of 0.5 molar sulfuric acid, and add two milliliters of methanol after cooling.Filter all samples using 0.45 micro meter PTFE syringe filters and inject 20 microliters into HPLC using an auto sampler. Monitor the absorbance at 254 nanometers and calculate the concentrations from a calibration curve of known dihydrosinapinic acid standard solutions. Sinapinic acid was synthesized in high purity and a greater than 95%yield from syringaldehyde using the Green Knoevenagel Condensation, the proposed mechanism of the step growth polymerization of 4-Acetoxy-dihydrosinapinic acid is shown here.Hydrogen one and MR measurements were taken during the polymerization process. When poly-S was hydrolyzed in sodium hydroxide, the molecularly recyclable polyester yielded the starting material dihydrosinapinic acid in less than 10 minutes. As confirmed by HBLC melting point analysis and hydrogen one and MR.Extended reaction times did not increase the yield.The thermal grams and GPC analysis of poly-S 1.0 and their successive generations poly-S 2.0 and polyester 3.0 after forced amorphicity with a tactic polystyrene are shown here. DSC analysis of poly-S shows a glass transition signal at 113 degrees Celsius and endothermic melting signal at 281 degrees Celsius. The polymers from re-polymerized sinapinic acid three eight poly-S 2.0 up and poly-H 3.0 exhibit similar thermal properties.Poly-S is a semi crystalline polymeric material because glass transition temperatures and melting signals are present in the thermograms of poly-S and their successive generations. GPC analysis after forced amorphicity with a tactic polystyrene displays a constant length of polymeric material throughout the different generations. While attempting the Green Knoevenagel reaction, please keep in mind that a correct temperature is used.A slightly higher temperature can lead to different site reactions. We have explored an example of a molecularly recyclable polymer. Closely related building blocks can follow the same procedure, or while maintaining thermal and mechanical properties.This method can be used in organic catalysis by demonstrating of the catalytic intermediates, as well in the still unexplored area of molecular recycling.

Research

Education

JoVE Core

JoVE Journal

Organic Chemistry

Chemistry

Unit 1

&alpha;-Carbon Chemistry: Enols, Enolates, and Enamines

SCIENTISTS IN ACTION

Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

Gyroid镍纳米结构的嵌段共聚物超分子

Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, ...

科研

化学

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

对磷酸增强富集制备高度多孔配位聚合物涂层的孔聚合物石柱的

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers

光动力疗法与混合导电高分子/富勒烯纳米颗粒光敏剂

In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next ...

Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering

单壁碳纳米管与热可逆嵌段共聚物及表征功能化小角度中子散射

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous ...

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry

热可逆交联橡胶通过的Diels-Alder反应的化学制备与性能

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ...

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

激光驱动的超快分子旋转直接成像

We present a method for visualizing laser-induced, ultrafast molecular rotational wave packet dynamics. We have developed a new 2-dimensional Coulomb ...

Microfluidic Dry-spinning and Characterization of Regenerated Silk Fibroin Fibers

微流控干纺及再生丝素纤维的表征

The protocol demonstrates a method for mimicking the spinning process of silkworm. In the native spinning process, the contracting spinning duct enables ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

电化学阻抗谱作为电化学速率常数估计的一种工具

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera

利用 iccd 摄像机对无氧环境下的三重收集有机化合物进行光物理表征

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables ...